Bindi Irwin has posted a tribute to her late father, "Crocodile Hunter" Steve Irwin, on what would have been his 55th birthday.

Irwin was just 8 years old when her father was killed by a stingray while filming a documentary on a reef off Australia in 2006. The now 18-year-old posted a picture on Instagram on Wednesday of her father smiling at a bird. She wrote in the caption, "Always in our hearts."